Process of treating iron and steel.



W. F. M. MoGARTY.

PROCESS OF TREATING IRON AHD STEEL. APPLICATION FILED NOV. 23, 190?.

. 9Q1,362. Patented 0c t.20,1908.

- EXHAUST Wihwgeg I UNIT S WILLIAM F. MASON I McCA R'TY, OF PLEASANTVILLE, NEW TO GEORGE O. EATON, ONE-FOURTH TO THOMA ALEXANDER J. GUTTMAN, OF N EW YORK, N. Y.

PROCESS OF 'TREALTINGiRUN'AND STEEL Epecific'ation of Letters'IPatent.

" Patented Oct. 20, 1908.

Application filed November 23, 1907. Serial N0.-&03,4l52.

To ctl'whom tt'may concern:

Be it known that 1, WILLIAM F. Mason MoCAn'rr, a citizen of the United States, residing at Pleasantville, in the county of VVestchcster and State of New York, have invented certain new and useful Improvements in Processes of Treating Iron and Steel, of which the following isa specification.

This invention relates to processes of treating iron and steel, and particularly steel, to produce theretronringots which are -:t'ree, or practically free, not only from sulfur and phosphorous but also from the occluded. or otherwise held gases which cause fissures, blow holes and like structural flaws in molded metal.

An importantadvantage of my invention resides in the fact that, in the practice of my process, cyanogen, which exercises a highly deleterious eilect upon steel, is practically Wholly eliminated.

Aiurther important advantage of my invention is that it is adapted to the treatment of metals or ores containing titanium or 'metals of like character, which are injurious to steel.

'In accomplishing the purposes of my invention I add to the materials from which the metal-is produced or to the metal after reduction, certain reagents which, by-their reaction upon the impurities, under the conditions of the process as hereinafter set forth, 'efiect'the elimination thereof.

I'have discovered that the contaminating impurities hereinbefore referred-to, can be. to a great extent, removed by adding to the ore, or to the reduced metal, one or more eh-lorids decomposable'at the'temperature of molten iron, preferably a niixture ot' calcium chlorid (CaUh) 'and sodiumchlorid '(NaCl) *audhlowing superheated steam or superheated steam and air through the molten metal, orsubjecting it, While in a :molten condition, to the action of a vacuum. I have alsodiscovered that, by using the above mentioned reagents and blowing superheated steam or superheated steam and air through the molten metal, the impurities of the latter may he'elimin-ated to an extent hitherto unohtainable, if such treat- =ment is combined with or followed by-the "subjection of the metal tothe action o'fa vacuum.

actionsoccur are such as to render it In carrying out any process in its preferred form, I addto an averagegrade of ore or to the molten iron or steel therefrom, approximately 25 pounds of calcium chlorid and 100 pounds of sodium chlorid to every ton of metal or to the ores from whichthis amount of metal may he reduced, the reduction of the ore being carried out'in accordance With the usual practice in the art. The amount of chlorid or chloi'ids to be added depends upon the character of the ore-or metal treated. A determination of the'na- 'ture'and amount of impurities Will'enable a. steel Worker-of some experience in using my process, to determine with fair accuracy just the amount of salts to he added.

If the metal'has been produced ill-{HBO dinary blast-furnace it must be transferred to a Bessemer"converter having a vacuum pump attachment of the character indicated in the accompanying drawing. It is advisable however to employ'a blast furnace in which the -meta] may also be refined; sucha furnace being illustrated in the drawiug referred to.

A ftertho addition of the calcium chlorid and sodium chlorid, superheated steam is blown through the metal, preferably in rapidly occurring intermittent jets, or air and superheated steam are alternately passed through the liquid metal and the latter is subjected to'the action of a vacuum. The vacuum treatment may follow the injection of the steam or air and steam or the exhaust pump maybe started when the steam on air and steam isturned on. The treatment with steam and vacuumis continued untilatest of the metal 'shoWsit to be freed from itslmrpurities. A little experience in-treatingiron and steel from-a certain sourcewill render it possible to determinethe proper-duration of the treatment with practical certainty.

\Vhile the conditions under'Whichtherc impossible to fully determine the exact'chemi'cal reactions Which-occur in the practice of=my process, it app'ears that the treatment with =one ormore chloridsand p'articul'arlychlo rids of calcium and sodium, particularly where superheated steam is inj'ected, causes -a reaction of dissociated 'chlorin with the sulfur, phosphorus and the -difiicultly' removable gases in the metal, to: produce therefrom gases, such for e-Xamplaas, sulfur ox- YORK, 'ASSIGNOR 0F ONE-mourn s M. ACKEN, AND ONE-'THIRTIETH'TO ids, hydrogen sulfid, hydrogen phosphid, chlorin sulfid and ammonia, which are not of a nature to be securely held by occlusion or otherwise in the molten metal, but may be readily removed therefrom, particularly by the action of a vacuum. The treatment is particularly noteworthy in that cyanogen contained in the molten metal, is decomposed with the formation of ammonia, which is particularly readily removed by the action of a vacuum. In treating metals or ores containing titanium or similar impurity, the latter forms compounds, with, it is thought, the chlorin and cyanogen present, which are readily removed by volatilization from the material treated.

In the practice of my process I may ad- VQIItIgGOHSlY employ the novel form of fur nace shown in vertical section in the accom= panying drawing, although my process may be carried out practically and Successfully, although not so advantageously, in other forms of furnaces or converters.

In the drawing 1 represents a furnace provided with a crucible 2 into which twyers 3 and at are arranged to discharge air and superheated steam respectively. Cocks 5 and 6 are provided to control the supply of air and steam. An outlet 7, adapted to be closed by a tire clay plug is provided in the crucible 2.

The body of the furnace is provided throughout the greater portion of its length with double walls 8 and 9 as illustrated. The inner wall depends from the upper solid portion :of the furnace wall and terminates in an open lower end 10 which is of annular shape and of reduced diameter, the said end extending down into the crucible 2 to a point below the level of the molten metal, which will be contained therein during the use of the furnace. v

Between the inner and outer walls of the furnace is an annular chamber 11 which is in communication with the crucible 2. The chamber 11 is com'iected with the interior of the furnace by numerous openings 12 ar ranged in the walls, above the meltingzone. The furnace is supplied with a cover 13 which forms a substantially air tight joint with the top of the furnace.

Adjacent the top of the furnace I provide a pipe M which is connected with a powerful exhaust pump, (not shown) by which air and the gases arising from the metal treated may be withdrawn, in the treatment of the metal as hercinbefore referred to. A brickwork support 15 may also be provided.

In the use of the furnace, in the preferred practice of my process, it is charged with ore, flux and fuel, with the addition of calcium and sodium chlori ds, before mentioned, and the charge treated in accordance with the usual practice. in the operation of blast furnaces. When the ore has been reduced,

the metal in the crucible 2 is subjected to the treatment with superheated steam or air and superheated steam and the vacuum pump set in operation to withdraw air and gases through the pipe 14-, as has been hereinbefore fully described.

It will be noted that, inasmuch as the chamber 11 and openings 12 provide a passage for the steam or air and steam, which has passed through the metal in crucible 2, it is not. necessary to force or draw the entire body of steam or air and steam injected into the metal, through the mass remaining in the body of the furnace.

I have not claimed herein the furnace which I have shown and described, as this invention will form the subject matter of a separate applicatibn which is now being prepared. a; a I

Metal treated by my process will be found to be practically wholly free from impurities, to have a close fibrous or lamellar structure, be wholly free from fissures, flaws, seams, blow holes and the like, and to be possessed of great ductility, malleability and tensile strength.

It is to be understood that known equivalents of the materials and steps hereinbefore recited may be employed without departing from the spirit of my invention or the scope 9 of the appended claims. it is also .to be understood that the treated metal may, without departing from my process, be withdrawn from the furnace into a mold, by and under the action of a vacuum, as. fully described in my copending application for a method of producing ingots free from blowholes, filed July 12, 1907, Serial Number 382,488.

Having thus described my invention, 1 claim:

1. A process of purifying iron and steel which consists in incorporating a chlorid therein and subjecting the metal, in a molten state, to the action of superheated steam.

A process of purifying iron and steel which consists in incorporating sodium chlorid therein and subjecting the metal, in a molten state, to the action of superheated steam.

3. A process of purifying iron and steel which consists in incorporating a chlorid. therein, and subjecting the metal, in a molten state, to the action of superheated steam and a vacuum.

4. A process of purifying iron and steel which consists in incorporating a chlorid therein and subjecting the metal, in a molten state, to the action of superheated steam, in intermittent jets or impulses and to the action of a vacuum.

5. A process of purifying iron and steel 1 which consists in incorporating sodium chlorid therein and subjecting the metal, in a molten state, to the action of superheated steam and a Vacuum.

6. A process of purifying iron and steel which consists in incorporating sotiium (fl1l(')ll(l therein and subjecting the metal, in u moiten state, to the action of superheated 5 steam in intermi tentjets or impulses and to the action of a vacuum.

7. A process of purifying iron and steel whit-h eonsi s in incorporating a chlorid therein, passing superheated steam through 10 the metal, While in a molten state, and then subjecting it to the action of a vacuum. 7

8. A process of purifying iron and steel which consists in incorporating ft chloricl therein, passing superheated steam in inter 15 mittent jets or impulses through the metal,

senses 3 While in a molten state, and then subjecting it to the action of a vacuum.

9. A process of purifying iron and steel which consists in incorporating a chlorid therein, passing superheated steam and air 20 through the metal, while in a molten state,

and then subjecting it to the action of a \ncuum.

In testimony whereof I aflix my signature in presence of two witnesses.

WILLIAM F. MASON MCCARTY.

Witnesses W. S. Moons, LAURA R. AUSTIN. 

